cosh - Man Page

hyperbolic cosine function

Library

Math library (libm, -lm)

Synopsis

#include <math.h>

double cosh(double x);
float coshf(float x);
long double coshl(long double x);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

coshf(), coshl():

    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

Description

These functions return the hyperbolic cosine of x, which is defined mathematically as:

cosh(x) = (exp(x) + exp(-x)) / 2

Return Value

On success, these functions return the hyperbolic cosine of x.

If x is a NaN, a NaN is returned.

If x is +0 or -0, 1 is returned.

If x is positive infinity or negative infinity, positive infinity is returned.

If the result overflows, a range error occurs, and the functions return +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.

Errors

See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Range error: result overflow

errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.

Attributes

For an explanation of the terms used in this section, see attributes(7).

InterfaceAttributeValue
cosh(), coshf(), coshl()Thread safetyMT-Safe

Standards

C99, POSIX.1-2001, POSIX.1-2008.

The variant returning double also conforms to SVr4, 4.3BSD.

Bugs

In glibc version 2.3.4 and earlier, an overflow floating-point (FE_OVERFLOW) exception is not raised when an overflow occurs.

See Also

acosh(3), asinh(3), atanh(3), ccos(3), sinh(3), tanh(3)

Referenced By

acosh(3), asinh(3), atanh(3), sinh(3), tanh(3).

The man pages coshf(3) and coshl(3) are aliases of cosh(3).

2022-10-09 Linux man-pages 6.01